Process and machine for surfacing glass



May 12, 1953 L. l.. c. DE BAY 2,637,949

PROCESS AND MACHINE FOR SURFACING GLASS Filed April 17, 19E! 2 Sheets-Sheet l w n cn:cn:

m Oo N May 12, 1953 l.. 1 c. DE BAY PROCESS AND MACHINE FOR SURFACING GLASS Filed April 17, 1951 2 Sheets-Sheet 2 Patented May 12, 1953 PROCESS AND MACHINE FOR SURFACING GLASS Lucien L. C. De Bay, Brussels, Belgium, assignor to Les Glaceries De La Sambre, Societe Anonyme, Auvelais, Belgium, a Belgian company Application April 17, 1951, Serial No. 221,349 In Belgium April 28, 1950 11 Claims.

It is known to grind and/or polish simultaneously the two faces of a ribbon or sheet of glass continuously leaving a lehr. In the processes employed for this purpose, the surfacing tools, that is to say the tools of cast iron or abrasive material for the grinding and the felt-lined polishers for the polishing, are disposed in pairs, the pressure exerted by the tools acting on the upper face of the sheet being supported by the tools working on the lower face.

Between the beams on which the grinding or polishing tools are mounted, the glass is supported and driven by rolls which generally consist of steel and may be coated with rubber. The glass sheet moves along a horizontal plane determined by the generatrices along which the driving rolls are situated and by the working Isurfaces of the tools mounted on the lower beams. As the tools become worn, the lower beams must be vertically adjusted to bring them periodically into contact with the lower face of the glass sheet.

It has already been proposed to employ abrasive or polishing rolls as surfacing tools, that is to say, as grinding or polishing tools, and to impart to these surfacing rolls, movements in the direction of their aXes. These rolls are preferably disposed in pairs, one above and one below the surface of the glass, their axes and working generatrices being situated in a common vertical plane which is either perpendicular or oblique in relation to the direction of forward feed of the glass.

The presen-t invention has for its object to increase the efficiency of machines comprising grinding and/or polishing rolls and to avoid the disadvantages connected with the necessity of adjusting the lower tools in the case of machines acting on the two faces of the glass.

In accordance with the present invention, the lower surfacing rolls and the upper surfacing rolls are actuated at different speeds of rotation such that their resultant acts in the direction in which the glass is yto be driven. Preferably, the speed of rotation of the lower rolls is the greater, and the speed of the upper rolls may then vary within wide limits, or it may even be negative, that is to say, directed in the direction opposite that corresponding to the forward feed of the glass. However, it is important that the resultant of the frictional forces be always directed in the direction of the feed of the glass, whether this resultant be obtained by a pair of rolls or by a group of pairs of rolls.

According to one feature of the invention, the

axial translational movements of the rolls of one pair are opposite to one ano-ther, that is to say that, with reference to the direction in which the glass is fed, the lower roll will move from right to left while the upper roll will move from left to right and vice versa. The opposition of the directions of movement may also be produced between `successive rolls in the horizontal plane. The forces acting on the glass transversely in relation to its direction of feed are thus reduced and a better equilibrium is obtained.

Another feature of the invention resides in the use of the surfacing rolls as driving rolls for the glass in combination with tools of other forms, it thus being unnecessary to provide special driving rolls for this purpose between the said tools. The surfacing rolls may in this case be employed, for example, in alternating arrangement at the same time as beams on which are mounted grinding and/or polishing members of conventional form (discs) or of any other suitable form. Since the rolls become worn at the same time as the other surfacing tools, the reduction of the diameter thereof by wear may be made such that their working generatrices are maintained in the hori zontal plane of contact of the lower beams, whereby this adjustment is rendered unnecessary.

The accompanying drawing shows by way of example a number of embodiments of the invention:

Figure 1 is an elevational side view,

Figure 2 is a plan view, and

Figure 3 is a section on the line III-III (Figure 1) of a pair of rolls moved axially in opposite directions and of the mechanisms for the actuation thereof.

Figure 4. is an elevational view, and

Figure 5 is a plan view of successive rolls moving in opposite directions.

Figure 6 is a diagrammatic elevational View, and

Figure 7 is a corresponding plan view of an alternate arrangement of beams provided with working discs and working rolls employed as driving roll-s.

In Figures 1 to 3, l is the glass sheet leaving a lehr and passing between upper rolls 2 and lower rolls 2 actuated with two movements, i. e. rotational and translational movements. The rolls 2, 2 preferably comprise a shaft 3, 3' having mounted thereon groups of discs between which are left gaps 4, il. The discs consist of cast iron or other abrasive material in the grinding arrangement, and of felt in the polishing arrangement. The rolls are arranged in pairs, the lower roll 2' supporting the effort exerted on the sheet by the upper roll E.

On rotation of a hand wheel 5 acting on a screwthreaded rod S, the working pressure is simultaneously exerted on the two faces of the glass sheet through a spring l. The rolls 2 and 2 are rotated by independent motors 8, 8 through gears Si, Si', sprocket wheels lll, lo and chains il, Il respectively.

The rotations imparted to the rolls 2 and 2 take place in lthe same direction (Figure 3) so that the lower roll 2 urges the sheet i in the clirection of its forward feed, while lthe upper roll 2. acts in the direction opposite that of the feed. The respective speeds of rotation of the rolls 2, 2 determined by the ratio between the number of teeth of each of the wheels le on the one hand and IQ on the other hand are such that the resultant of the frictional forces is in the direction of forward feed of the sheet indicated by the arrow a.

The speed of the motors 8 is adjustable to allow of adjusting, if desired, the speed of rotation of the rolls Z in order to compensate for the differences of diameter due to the wear of the felts.

In the embodiment illustrated, a reciprocating movement is imparted to the rolls in the axial direction thereof by the following mechanism: a worm l2 fast with the shaft 3 turns the helicoidal wheel I3 about its shaft Hi on which is mounted a disc iti provided with a crank pin iti connected by a link i7 to the link pin i8 xed to the fixed frame is'. The rotation of the wheel i3 is thus accompanied by a reciprocating movement of this wheel. and of its support 2G, which slides by means of its shoe 2i on a guide rod 22. The reciprocatingr movement of the support 2li is imparted to the shaft 3', the rolls 2 and the frame 23 mounted on pulleys 2li. The frame 23 supports the motor S and the transmission 9. le', Il actuating the shaft 3 and moves on the fixed frame 25 under the action of the link l1.

Mounted on rollers il' on the fixed frame i3' is a carriage 25 supporting the motor and the transmission 9, ifi, H for the rotation of the shaft 3. A rocking member 2s pivotally mounted at 28 on the frame Ii transmits the movements of a bar connected to the support 2i) in the opposite direction to the carriage 25. Thus, the two rolls 2, 2 are actuated simultaneously in opposite directions, one of them being at the end of its travel towards the right when the other is at the end of its travel towards the left. By means of this arrangement, the transverse 'thrusts on the glass can be balanced.

The progressive wear of the rolls tends to move the lower roll out of the working plane and may thus create dangerous stresses in the glass. The jacks 3 l, 3i operated simultaneously by the hand wheel 32 allow, if necessary, of lifting the two frames 2t and the parts mounted on them in order to return the generatrices of the rolls 2 into the horizontal working plane.

In order to reduce the stresses in the glass, it is advantageous not only to impart opposite axial movements to the two rolls of each pair, but also to move the successive rolls or the successive groups of rolls axially in opposite directions. Figures a and 5 show an arrangement of pairs of working rolls 2, 2', in which all the upper rolls of uneven order, for example, are situated in the left-hand dead centre position when all the upper rolls of even order are situated in the right-hand dead centre position.

As is shown in Figure Ll, the arrangement of surfacing rolls actuated in accordance with the invention, that is, in such manner that the resultant of their frictional forces on the glass is exerted in the direction of forward feed of the glass sheet, renders it unnecessary to provide special driving rolls, the surfacing rolls serving simultaneously as supporting and driving rolls.

In another embodiment of the invention, normal surfacing tools, such as grinding rubbers and polishing discs, are employed in combination with working rolls, the latter then acting as driving rolls and simultaneously co-operating with the other tools to improve the work. Moreover, the

on the rolls and tools may be rendered substantially equal, so that it is possible to eliminate or at least to reduce the frequent adjustments which are necessary in the usual machines to for the weer of the tools in relation to the driving rolls.

An arrangement of this nature is shown in Figures 6 and 7, in which the pairs of rolls il, 2 serving both as surfacing rolls and as driving rolls alternate with pairs of beams lfl, provided with grinding or polishing discs 35, 3V. Naturally, a number of pairs of rolls may be disposed one afterthe other between pairs of beams and the latter may be provided with any number of working tools, the form of which may vary, the arrangement illusrated merely being intended as an example. The rolls E, 2' and the beams 36, 34 may also be actuated with reciprocating movements in the direction of their longitudinal axes, as explained in the foregoing.

Further modications may obviously be made to ther examples described and illustrated withouty departing from the scope of the invention.

I claim:

l.r The method of producing finish to glass sheets, consisting in imparting a continuous movement of translation to each sheet by rotary surfacing rollers operating against opposite faces ofjtzhesheet, maintaining a substantially constant differential ratio of effective driving action of said surfacing rollers upon the opposite faces of the glass and imparting reciprocating axial motion to said surfacing rollers the faster moving roll 0f each pair being moved in opposite phase to the (xo-operating slower moving roll.

2. The method of producing finish to glass sheets consisting in imparting a continuous movement of translation to each sheet by a plurality of pairs of rotaryv surfacing rollers, maintaining a substantially constant differential ratio of effective driving action of said surfacing rollers upon the opposite faces of the glass and imparting reciprocating axial motion to said surfacing rollers, the rotary grinders of each pair reciprocating in constantly opposite phase.

3. The method of producing finish to glass Sheets consisting in imparting a continuous movementY of translation to each sheet by a plurality of pairs 0f rotary surfacing rollers, maintaining a substantially constant differential ratio of cffective driving action of the surfacing rollers upon the opposite faces of the glass, imparting reciprocating axial motion to said surfacing rollers, the surfacing rollers of each pair reciprocating in constantly opposite phase and the consecutive rollers on the same side of the glass reciprocating in constantly opposite phase.

4. The method of producing finish to glass sheet', consisting in imparting a continuous move- 

